J/ApJ/776/L20ivo://CDS.VizieR/J/ApJ/776/L20doi:10.26093/cds/vizier.17769020CDSMeech K.J.Yang B.Kleyna J.Ansdell M.Chiang H.-F.Hainaut O.,Vincent J.-B.Boehnhardt H.Fitzsimmons A.Rector T.Riesen T.,Keane J.V.Reipurth B.Hsieh H.H.Michaud P.Milani G.Bryssinck E.,Ligustri R.Trabatti R.Tozzi G.-P.Mottola S.Kuehrt E.Bhatt B.,Sahu D.Lisse C.Denneau L.Jedicke R.Magnier E.Wainscoat R.2017-06-13T11:08:07Z2015-04-27T14:04:49ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frcometsinfrared-photometryvisible-astronomyphotometryWe report photometric observations for comet C/2012 S1 (ISON) obtained during the time period immediately after discovery (r=6.28AU) until it moved into solar conjunction in mid-2013 June using the UH2.2m, and Gemini North 8m telescopes on Mauna Kea, the Lowell 1.8m in Flagstaff, the Calar Alto 1.2m telescope in Spain, the VYSOS-5 telescopes on Mauna Loa Hawaii and data from the CARA network. Additional pre-discovery data from the Pan STARRS1 survey extends the light curve back to 2011 September 30 (r=9.4AU). The images showed a similar tail morphology due to small micron sized particles throughout 2013. Observations at submillimeter wavelengths using the James Clerk Maxwell Telescope on 15 nights between 2013 March 9 (r=4.52AU) and June 16 (r=3.35AU) were used to search for CO and HCN rotation lines. No gas was detected, with upper limits for CO ranging between 3.5-4.5x10^27^molecules/s. Combined with published water production rate estimates we have generated ice sublimation models consistent with the photometric light curve. The inbound light curve is likely controlled by sublimation of CO_2_. At these distances water is not a strong contributor to the outgassing. We also infer that there was a long slow outburst of activity beginning in late 2011 peaking in mid-2013 January (r~5AU) at which point the activity decreased again through 2013 June. We suggest that this outburst was driven by CO injecting large water ice grains into the coma. Observations as the comet came out of solar conjunction seem to confirm our models.2013ApJ...776L..20Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/776/L20CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/astorb : Orbits of Minor Planets (Bowell+ 2014)B/comets : Database of the orbital elements of comets (Rocher, 2007)J/A+A/575/A52 : Short-term variability comet C/2012S1 (Santos-Sanz+, 2015)J/A+A/564/L2 : CH3OH line param. in comets ISON and Lovejoy (Agundez+, 2014)J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)http://www.brucegary.net/ISON/ : Comet ISON web pagehttp://www.aavso.org/apass : APASS: the AAVSO photometric all-sky surveyhttp://www.ifa.hawaii.edu/~reipurth/VYSOS : VYSOS variable young stellarhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/776/L20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/776/L20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/776/L20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/776/L20https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/776/L20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/776/L20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/776/L20/table2CARA and VYSOS observationse_mag[0.02/0.3] Uncertainty in magmagstat.error;phot.magfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT date of the observationtime.epoch;obsnullableTelTelescope used in the observationinstr.setup;obscharN? Number of exposures; VYSOS observations onlymeta.numberintnullableExp? Total exposure time; VYSOS observations onlystime.duration;obs.exposureintnullableFilt[Rr] Filter used in the observation (r or R)instr.setup;obscharr[3.3/6.3] Heliocentric distanceAUpos.distance;pos.heliocentricfloatDelta[4/6.7] Geocentric distance {Delta}AUpos.distance;pos.geocentricfloatalpha[1.8/13.7] Solar phase angle {alpha}degpos.phaseAngfloatTA[-175/-173] True anomalydegsrc.orbital.meanAnomalydoublePASun[0/360] Position angle of antisolar vector (1)degpos.posAngfloatPAv[0/360] Position angle of negative velocity vector (1)degpos.posAngfloatmag[14.6/17.7] Observed magnitude in Filtmagphot.magfloat